1. Field of the Invention
This invention relates to filter press plates used in a filter press assembly, and more specifically relates to filter press plates configured with replaceable, wear resistant members associated with the filtrate ports of a filter plate which extend the life of the filter press plate.
2. Description of the Related Art
Filter press assemblies are used in many industries to process feed slurries resulting from a given process, such as mineral concentrate dewatering. Filter press assemblies involve separating a solids component from the liquid component of the feed slurry to produce a solid, dewatered cake of material. The remaining or separated liquid filtrate is channeled out of the filter press assembly for re-processing or disposal.
A filter press assembly comprises a plurality of planar filter plates which are aligned and adjacently arranged in a horizontal stack. Each filter plate has a peripheral edge or frame and one or more faces recessed from the rim or frame so that when two filter plates are positioned adjacent one another, a space is formed therebetween. Each filter plate also has a feed port which, when the filter plates are aligned and in adjacent arrangement, provides a feed channel into which a feed slurry is introduced.
The feed slurry enters the space formed between adjacent filter plates and the larger solids of the slurry are deposited while the liquid component drains away from the space and is channeled away from the filter press assembly. Typically, each face of a filter plate is covered with an arrangement of raised bosses or pips which form channels therebetween through which the liquid filtrate is communicated toward openings formed near the periphery of the filter plate. The openings are in fluid communication with a filtrate outlet through which the filtrate then empties.
In operation, each filter plate is typically covered with a filter media, usually made of cloth, and the feed slurry is introduced between adjacent layers of filter media. High velocity air is introduced between adjacent filter plates to air sweep the solids accumulating between the two layers of filter media and to force the filtrate through the filter media. A substantially dry and solid cake of solids material results. The liquid filtrate, being subjected to high velocity air, passes through the filter media and is channeled along the face of the filter plate at high velocity. The filtrate then enters into the openings and through the filtrate outlet at high velocity.
When processing feed slurries which have abrasive components that are small enough to pass through the filter media, or through holes worn in the filter media, the high-velocity filtrate moving along the faces of the filter plate and into the filtrate openings cause a significant amount of damage to the filter plate. Not only do the openings become worn and degraded, but the filtrate outlet becomes abraded and worn. Eventually the filtrate openings and filtrate outlets of the filter plate become so worn that leakage occurs between adjacent filter plates and the filter press assembly is unable to operate efficiently, or at all. The worn filter plates cannot be repaired and must be discarded and replaced with new filter plates. Replacing the filter plates is very expensive.
Thus, it would be advantageous in the art to structure a filter press plate to have increased resistance to degradation caused by the movement of high velocity abrasive filtrate and which would enable fast, easy and inexpensive repair of the filter plate when degradation does occur so that the life of the filter plate can be extended, thereby reducing operating costs.
In accordance with the present invention, a filter press plate is structured with replaceable wear elements which provide wear resistance to the filtrate openings and filtrate outlet of the filter plate, thereby extending the life of the filter plate and facilitating easy and inexpensive repair of the filter plate when degradation of the wear element occurs.
In a filter plate of the present invention, the filter plate is structured to receive inserted replaceable wear elements in concert with the filtrate opening or outlet of the filter plate. The wear elements are preferably formed of a material which is particularly resistant to wear or degradation that may be caused by contact with high-velocity abrasive material. The wear elements are positioned on the filter plate to receive abrasive filtrate in transit to and through the filtrate outlet of the filter plate. Thus, the wear elements are subjected to the degrading effects of the abrasive filtrate, in the area of the filter plate where the most significant amount of degradation occurs, and the replaceability of the wear elements enables the filter plate to essentially be refurbished for further use, thereby extending the conventional life of the filter plate.
The wear elements of the present invention comprise one or more wear plates configured to fit over a portion of the recessed face of a filter plate, a filtrate channel insert and a filtrate outlet insert. The wear plates, filtrate channel insert and filtrate outlet insert are each constructed of a suitable wear-resistant material to withstand contact with abrasive material, but each is also readily replaceable when degraded.
A filter plate is described being structured with wear elements in accordance with the present invention. However, the wear elements of the present invention are also adaptable for retrofitting to virtually any type, style or manufacture of filter press plate.